package consul import ( "fmt" "io" "log" "sync" "time" "github.com/armon/go-metrics" "github.com/hashicorp/consul/api" "github.com/hashicorp/consul/consul/state" "github.com/hashicorp/consul/consul/structs" "github.com/hashicorp/go-msgpack/codec" "github.com/hashicorp/raft" ) // msgpackHandle is a shared handle for encoding/decoding msgpack payloads var msgpackHandle = &codec.MsgpackHandle{} // consulFSM implements a finite state machine that is used // along with Raft to provide strong consistency. We implement // this outside the Server to avoid exposing this outside the package. type consulFSM struct { logOutput io.Writer logger *log.Logger path string // stateLock is only used to protect outside callers to State() from // racing with Restore(), which is called by Raft (it puts in a totally // new state store). Everything internal here is synchronized by the // Raft side, so doesn't need to lock this. stateLock sync.RWMutex state *state.Store gc *state.TombstoneGC } // consulSnapshot is used to provide a snapshot of the current // state in a way that can be accessed concurrently with operations // that may modify the live state. type consulSnapshot struct { state *state.Snapshot } // snapshotHeader is the first entry in our snapshot type snapshotHeader struct { // LastIndex is the last index that affects the data. // This is used when we do the restore for watchers. LastIndex uint64 } // NewFSM is used to construct a new FSM with a blank state func NewFSM(gc *state.TombstoneGC, logOutput io.Writer) (*consulFSM, error) { stateNew, err := state.NewStateStore(gc) if err != nil { return nil, err } fsm := &consulFSM{ logOutput: logOutput, logger: log.New(logOutput, "", log.LstdFlags), state: stateNew, gc: gc, } return fsm, nil } // State is used to return a handle to the current state func (c *consulFSM) State() *state.Store { c.stateLock.RLock() defer c.stateLock.RUnlock() return c.state } func (c *consulFSM) Apply(log *raft.Log) interface{} { buf := log.Data msgType := structs.MessageType(buf[0]) // Check if this message type should be ignored when unknown. This is // used so that new commands can be added with developer control if older // versions can safely ignore the command, or if they should crash. ignoreUnknown := false if msgType&structs.IgnoreUnknownTypeFlag == structs.IgnoreUnknownTypeFlag { msgType &= ^structs.IgnoreUnknownTypeFlag ignoreUnknown = true } switch msgType { case structs.RegisterRequestType: return c.applyRegister(buf[1:], log.Index) case structs.DeregisterRequestType: return c.applyDeregister(buf[1:], log.Index) case structs.KVSRequestType: return c.applyKVSOperation(buf[1:], log.Index) case structs.SessionRequestType: return c.applySessionOperation(buf[1:], log.Index) case structs.ACLRequestType: return c.applyACLOperation(buf[1:], log.Index) case structs.TombstoneRequestType: return c.applyTombstoneOperation(buf[1:], log.Index) case structs.CoordinateBatchUpdateType: return c.applyCoordinateBatchUpdate(buf[1:], log.Index) case structs.PreparedQueryRequestType: return c.applyPreparedQueryOperation(buf[1:], log.Index) case structs.TxnRequestType: return c.applyTxn(buf[1:], log.Index) case structs.AutopilotRequestType: return c.applyAutopilotUpdate(buf[1:], log.Index) default: if ignoreUnknown { c.logger.Printf("[WARN] consul.fsm: ignoring unknown message type (%d), upgrade to newer version", msgType) return nil } panic(fmt.Errorf("failed to apply request: %#v", buf)) } } func (c *consulFSM) applyRegister(buf []byte, index uint64) interface{} { defer metrics.MeasureSince([]string{"consul", "fsm", "register"}, time.Now()) var req structs.RegisterRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } // Apply all updates in a single transaction if err := c.state.EnsureRegistration(index, &req); err != nil { c.logger.Printf("[INFO] consul.fsm: EnsureRegistration failed: %v", err) return err } return nil } func (c *consulFSM) applyDeregister(buf []byte, index uint64) interface{} { defer metrics.MeasureSince([]string{"consul", "fsm", "deregister"}, time.Now()) var req structs.DeregisterRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } // Either remove the service entry or the whole node. The precedence // here is also baked into vetDeregisterWithACL() in acl.go, so if you // make changes here, be sure to also adjust the code over there. if req.ServiceID != "" { if err := c.state.DeleteService(index, req.Node, req.ServiceID); err != nil { c.logger.Printf("[INFO] consul.fsm: DeleteNodeService failed: %v", err) return err } } else if req.CheckID != "" { if err := c.state.DeleteCheck(index, req.Node, req.CheckID); err != nil { c.logger.Printf("[INFO] consul.fsm: DeleteNodeCheck failed: %v", err) return err } } else { if err := c.state.DeleteNode(index, req.Node); err != nil { c.logger.Printf("[INFO] consul.fsm: DeleteNode failed: %v", err) return err } } return nil } func (c *consulFSM) applyKVSOperation(buf []byte, index uint64) interface{} { var req structs.KVSRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "kvs", string(req.Op)}, time.Now()) switch req.Op { case api.KVSet: return c.state.KVSSet(index, &req.DirEnt) case api.KVDelete: return c.state.KVSDelete(index, req.DirEnt.Key) case api.KVDeleteCAS: act, err := c.state.KVSDeleteCAS(index, req.DirEnt.ModifyIndex, req.DirEnt.Key) if err != nil { return err } return act case api.KVDeleteTree: return c.state.KVSDeleteTree(index, req.DirEnt.Key) case api.KVCAS: act, err := c.state.KVSSetCAS(index, &req.DirEnt) if err != nil { return err } return act case api.KVLock: act, err := c.state.KVSLock(index, &req.DirEnt) if err != nil { return err } return act case api.KVUnlock: act, err := c.state.KVSUnlock(index, &req.DirEnt) if err != nil { return err } return act default: err := fmt.Errorf("Invalid KVS operation '%s'", req.Op) c.logger.Printf("[WARN] consul.fsm: %v", err) return err } } func (c *consulFSM) applySessionOperation(buf []byte, index uint64) interface{} { var req structs.SessionRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "session", string(req.Op)}, time.Now()) switch req.Op { case structs.SessionCreate: if err := c.state.SessionCreate(index, &req.Session); err != nil { return err } return req.Session.ID case structs.SessionDestroy: return c.state.SessionDestroy(index, req.Session.ID) default: c.logger.Printf("[WARN] consul.fsm: Invalid Session operation '%s'", req.Op) return fmt.Errorf("Invalid Session operation '%s'", req.Op) } } func (c *consulFSM) applyACLOperation(buf []byte, index uint64) interface{} { var req structs.ACLRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "acl", string(req.Op)}, time.Now()) switch req.Op { case structs.ACLForceSet, structs.ACLSet: if err := c.state.ACLSet(index, &req.ACL); err != nil { return err } return req.ACL.ID case structs.ACLDelete: return c.state.ACLDelete(index, req.ACL.ID) default: c.logger.Printf("[WARN] consul.fsm: Invalid ACL operation '%s'", req.Op) return fmt.Errorf("Invalid ACL operation '%s'", req.Op) } } func (c *consulFSM) applyTombstoneOperation(buf []byte, index uint64) interface{} { var req structs.TombstoneRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "tombstone", string(req.Op)}, time.Now()) switch req.Op { case structs.TombstoneReap: return c.state.ReapTombstones(req.ReapIndex) default: c.logger.Printf("[WARN] consul.fsm: Invalid Tombstone operation '%s'", req.Op) return fmt.Errorf("Invalid Tombstone operation '%s'", req.Op) } } // applyCoordinateBatchUpdate processes a batch of coordinate updates and applies // them in a single underlying transaction. This interface isn't 1:1 with the outer // update interface that the coordinate endpoint exposes, so we made it single // purpose and avoided the opcode convention. func (c *consulFSM) applyCoordinateBatchUpdate(buf []byte, index uint64) interface{} { var updates structs.Coordinates if err := structs.Decode(buf, &updates); err != nil { panic(fmt.Errorf("failed to decode batch updates: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "coordinate", "batch-update"}, time.Now()) if err := c.state.CoordinateBatchUpdate(index, updates); err != nil { return err } return nil } // applyPreparedQueryOperation applies the given prepared query operation to the // state store. func (c *consulFSM) applyPreparedQueryOperation(buf []byte, index uint64) interface{} { var req structs.PreparedQueryRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "prepared-query", string(req.Op)}, time.Now()) switch req.Op { case structs.PreparedQueryCreate, structs.PreparedQueryUpdate: return c.state.PreparedQuerySet(index, req.Query) case structs.PreparedQueryDelete: return c.state.PreparedQueryDelete(index, req.Query.ID) default: c.logger.Printf("[WARN] consul.fsm: Invalid PreparedQuery operation '%s'", req.Op) return fmt.Errorf("Invalid PreparedQuery operation '%s'", req.Op) } } func (c *consulFSM) applyTxn(buf []byte, index uint64) interface{} { var req structs.TxnRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "txn"}, time.Now()) results, errors := c.state.TxnRW(index, req.Ops) return structs.TxnResponse{ Results: results, Errors: errors, } } func (c *consulFSM) applyAutopilotUpdate(buf []byte, index uint64) interface{} { var req structs.AutopilotSetConfigRequest if err := structs.Decode(buf, &req); err != nil { panic(fmt.Errorf("failed to decode request: %v", err)) } defer metrics.MeasureSince([]string{"consul", "fsm", "autopilot"}, time.Now()) if req.CAS { act, err := c.state.AutopilotCASConfig(index, req.Config.ModifyIndex, &req.Config) if err != nil { return err } return act } return c.state.AutopilotSetConfig(index, &req.Config) } func (c *consulFSM) Snapshot() (raft.FSMSnapshot, error) { defer func(start time.Time) { c.logger.Printf("[INFO] consul.fsm: snapshot created in %v", time.Now().Sub(start)) }(time.Now()) return &consulSnapshot{c.state.Snapshot()}, nil } // Restore streams in the snapshot and replaces the current state store with a // new one based on the snapshot if all goes OK during the restore. func (c *consulFSM) Restore(old io.ReadCloser) error { defer old.Close() // Create a new state store. stateNew, err := state.NewStateStore(c.gc) if err != nil { return err } // Set up a new restore transaction restore := stateNew.Restore() defer restore.Abort() // Create a decoder dec := codec.NewDecoder(old, msgpackHandle) // Read in the header var header snapshotHeader if err := dec.Decode(&header); err != nil { return err } // Populate the new state msgType := make([]byte, 1) for { // Read the message type _, err := old.Read(msgType) if err == io.EOF { break } else if err != nil { return err } // Decode switch structs.MessageType(msgType[0]) { case structs.RegisterRequestType: var req structs.RegisterRequest if err := dec.Decode(&req); err != nil { return err } if err := restore.Registration(header.LastIndex, &req); err != nil { return err } case structs.KVSRequestType: var req structs.DirEntry if err := dec.Decode(&req); err != nil { return err } if err := restore.KVS(&req); err != nil { return err } case structs.TombstoneRequestType: var req structs.DirEntry if err := dec.Decode(&req); err != nil { return err } // For historical reasons, these are serialized in the // snapshots as KV entries. We want to keep the snapshot // format compatible with pre-0.6 versions for now. stone := &state.Tombstone{ Key: req.Key, Index: req.ModifyIndex, } if err := restore.Tombstone(stone); err != nil { return err } case structs.SessionRequestType: var req structs.Session if err := dec.Decode(&req); err != nil { return err } if err := restore.Session(&req); err != nil { return err } case structs.ACLRequestType: var req structs.ACL if err := dec.Decode(&req); err != nil { return err } if err := restore.ACL(&req); err != nil { return err } case structs.CoordinateBatchUpdateType: var req structs.Coordinates if err := dec.Decode(&req); err != nil { return err } if err := restore.Coordinates(header.LastIndex, req); err != nil { return err } case structs.PreparedQueryRequestType: var req structs.PreparedQuery if err := dec.Decode(&req); err != nil { return err } if err := restore.PreparedQuery(&req); err != nil { return err } case structs.AutopilotRequestType: var req structs.AutopilotConfig if err := dec.Decode(&req); err != nil { return err } if err := restore.Autopilot(&req); err != nil { return err } default: return fmt.Errorf("Unrecognized msg type: %v", msgType) } } restore.Commit() // External code might be calling State(), so we need to synchronize // here to make sure we swap in the new state store atomically. c.stateLock.Lock() stateOld := c.state c.state = stateNew c.stateLock.Unlock() // Signal that the old state store has been abandoned. This is required // because we don't operate on it any more, we just throw it away, so // blocking queries won't see any changes and need to be woken up. stateOld.Abandon() return nil } func (s *consulSnapshot) Persist(sink raft.SnapshotSink) error { defer metrics.MeasureSince([]string{"consul", "fsm", "persist"}, time.Now()) // Register the nodes encoder := codec.NewEncoder(sink, msgpackHandle) // Write the header header := snapshotHeader{ LastIndex: s.state.LastIndex(), } if err := encoder.Encode(&header); err != nil { sink.Cancel() return err } if err := s.persistNodes(sink, encoder); err != nil { sink.Cancel() return err } if err := s.persistSessions(sink, encoder); err != nil { sink.Cancel() return err } if err := s.persistACLs(sink, encoder); err != nil { sink.Cancel() return err } if err := s.persistKVs(sink, encoder); err != nil { sink.Cancel() return err } if err := s.persistTombstones(sink, encoder); err != nil { sink.Cancel() return err } if err := s.persistPreparedQueries(sink, encoder); err != nil { sink.Cancel() return err } if err := s.persistAutopilot(sink, encoder); err != nil { sink.Cancel() return err } return nil } func (s *consulSnapshot) persistNodes(sink raft.SnapshotSink, encoder *codec.Encoder) error { // Get all the nodes nodes, err := s.state.Nodes() if err != nil { return err } // Register each node for node := nodes.Next(); node != nil; node = nodes.Next() { n := node.(*structs.Node) req := structs.RegisterRequest{ Node: n.Node, Address: n.Address, TaggedAddresses: n.TaggedAddresses, } // Register the node itself sink.Write([]byte{byte(structs.RegisterRequestType)}) if err := encoder.Encode(&req); err != nil { return err } // Register each service this node has services, err := s.state.Services(n.Node) if err != nil { return err } for service := services.Next(); service != nil; service = services.Next() { sink.Write([]byte{byte(structs.RegisterRequestType)}) req.Service = service.(*structs.ServiceNode).ToNodeService() if err := encoder.Encode(&req); err != nil { return err } } // Register each check this node has req.Service = nil checks, err := s.state.Checks(n.Node) if err != nil { return err } for check := checks.Next(); check != nil; check = checks.Next() { sink.Write([]byte{byte(structs.RegisterRequestType)}) req.Check = check.(*structs.HealthCheck) if err := encoder.Encode(&req); err != nil { return err } } } // Save the coordinates separately since they are not part of the // register request interface. To avoid copying them out, we turn // them into batches with a single coordinate each. coords, err := s.state.Coordinates() if err != nil { return err } for coord := coords.Next(); coord != nil; coord = coords.Next() { sink.Write([]byte{byte(structs.CoordinateBatchUpdateType)}) updates := structs.Coordinates{coord.(*structs.Coordinate)} if err := encoder.Encode(&updates); err != nil { return err } } return nil } func (s *consulSnapshot) persistSessions(sink raft.SnapshotSink, encoder *codec.Encoder) error { sessions, err := s.state.Sessions() if err != nil { return err } for session := sessions.Next(); session != nil; session = sessions.Next() { sink.Write([]byte{byte(structs.SessionRequestType)}) if err := encoder.Encode(session.(*structs.Session)); err != nil { return err } } return nil } func (s *consulSnapshot) persistACLs(sink raft.SnapshotSink, encoder *codec.Encoder) error { acls, err := s.state.ACLs() if err != nil { return err } for acl := acls.Next(); acl != nil; acl = acls.Next() { sink.Write([]byte{byte(structs.ACLRequestType)}) if err := encoder.Encode(acl.(*structs.ACL)); err != nil { return err } } return nil } func (s *consulSnapshot) persistKVs(sink raft.SnapshotSink, encoder *codec.Encoder) error { entries, err := s.state.KVs() if err != nil { return err } for entry := entries.Next(); entry != nil; entry = entries.Next() { sink.Write([]byte{byte(structs.KVSRequestType)}) if err := encoder.Encode(entry.(*structs.DirEntry)); err != nil { return err } } return nil } func (s *consulSnapshot) persistTombstones(sink raft.SnapshotSink, encoder *codec.Encoder) error { stones, err := s.state.Tombstones() if err != nil { return err } for stone := stones.Next(); stone != nil; stone = stones.Next() { sink.Write([]byte{byte(structs.TombstoneRequestType)}) // For historical reasons, these are serialized in the snapshots // as KV entries. We want to keep the snapshot format compatible // with pre-0.6 versions for now. s := stone.(*state.Tombstone) fake := &structs.DirEntry{ Key: s.Key, RaftIndex: structs.RaftIndex{ ModifyIndex: s.Index, }, } if err := encoder.Encode(fake); err != nil { return err } } return nil } func (s *consulSnapshot) persistPreparedQueries(sink raft.SnapshotSink, encoder *codec.Encoder) error { queries, err := s.state.PreparedQueries() if err != nil { return err } for _, query := range queries { sink.Write([]byte{byte(structs.PreparedQueryRequestType)}) if err := encoder.Encode(query); err != nil { return err } } return nil } func (s *consulSnapshot) persistAutopilot(sink raft.SnapshotSink, encoder *codec.Encoder) error { autopilot, err := s.state.Autopilot() if err != nil { return err } sink.Write([]byte{byte(structs.AutopilotRequestType)}) if err := encoder.Encode(autopilot); err != nil { return err } return nil } func (s *consulSnapshot) Release() { s.state.Close() }